Water Resources Engineering

Larry W. Mays is Professor of Civil and Environmental Engineering at Arizona State University and former chair of the department. He was formerly Director of the Center for Research in Water Resources at The University of Texas at Austin, where he also held an Engineering Foundation Endowed Professorship. A registered professional engineer in seven states and a registered professional hydrologist, he has served as a consultant to many organizations. He was the editor-in-chief of Reliability Analysis of Water Distribution Systems (ASCE) and co-editor of Computer Modeling of Free Surface and Pressurized Flows. Among his honors include a distinguished alumnus award from the University of Illinois at Urbana-Champaign in 1999.

About the Author iii

Acknowledgments v

Preface vi

Chapter 1 Introduction 1

1.1 Background 1

1.2 The World’s Freshwater Resources 10

1.3 Water Use in the United States 14

1.4 Systems of Units 16

1.5 The Future of Water Resources 18

1.6 Water–Energy Nexus 19

Chapter 2 Water Resources Sustainability 25

2.1 What is Water Resources Sustainability? 25

2.2 Challenges to Water Resources Sustainability 28

2.3 Surface Water System—The Colorado River Basin 48

2.4 Groundwater Systems—The Edwards Aquifer, Texas 53

2.5 Water Budgets 57

2.6 Examples of Water Resources Unsustainability 63

Chapter 3 Hydraulic Processes: Flow and Hydrostatic Forces 73

3.1 Principles 73

3.2 Control Volume Approach for Hydrosystems 80

3.3 Continuity 82

3.4 Energy 84

3.5 Momentum 88

3.6 Pressure and Pressure Forces in Static Fluids 89

3.7 Velocity Distribution 94

Chapter 4 Hydraulic Processes: Pressurized Pipe Flow 99

4.1 Classification of Flow 99

4.2 Pressurized (Pipe) Flow 102

4.3 Headlosses 106

4.4 Forces in Pipe Flow 116

4.5 Pipe Flow in Simple Networks 119

Chapter 5 Hydraulic Processes: Open-Channel Flow 127

5.1 Steady Uniform Flow 127

5.2 Specific Energy, Momentum, and Specific Force 138

5.3 Steady, Gradually Varied Flow 148

5.4 Gradually Varied Flow for Natural Channels 155

5.5 Rapidly Varied Flow 166

5.6 Discharge Measurement 172

Chapter 6 Hydraulic Processes: Groundwater Flow 183

6.1 Groundwater Concepts 183

6.2 Saturated Flow 191

6.3 Steady-State One-Dimensional Flow 196

6.4 Steady-State Well Hydraulics 199

6.5 Transient Well Hydraulics—Confined Conditions 205

6.6 Transient Well Hydraulics—Unconfined Conditions 215

6.7 Transient Well Hydraulics—Leaky Aquifer Conditions 216

6.8 Boundary Effects: Image Well Theory 217

6.9 Simulation of Groundwater Systems 225

Chapter 7 Hydrologic Processes 233

7.1 Introduction to Hydrology 233

7.2 Precipitation (Rainfall) 243

7.3 Evaporation 269

7.4 Infiltration 277

Chapter 8 Surface Runoff 291

8.1 Drainage Basins and Storm Hydrographs 291

8.2 Hydrologic Losses, Rainfall Excess, and Hydrograph Components 295

8.3 Rainfall-Runoff Analysis Using Unit Hydrograph Approach 299

8.4 Synthetic Unit Hydrographs 302

8.5 S-Hydrographs 307

8.6 NRCS (SCS) Rainfall-Runoff Relation 309

8.7 Curve Number Estimation and Abstractions 311

8.8 NRCS (SCS) Unit Hydrograph Procedure 318

8.9 Kinematic-Wave Overland Flow Runoff Model 322

8.10 Computer Models for Rainfall-Runoff Analysis 328

Chapter 9 Reservoir and Stream Flow Routing 333

9.1 Routing 333

9.2 Hydrologic Reservoir Routing 334

9.3 Hydrologic River Routing 338

9.4 Hydraulic (Distributed) Routing 342

9.5 Kinematic Wave Model for Channels 348

9.6 Muskingum–Cunge Model 353

9.7 Implicit Dynamic Wave Model 354

Chapter 10 Probability, Risk, and Uncertainty Analysis for Hydrologic and Hydraulic Design 361

10.1 Probability Concepts 361

10.2 Commonly Used Probability Distributions 364

10.3 Hydrologic Design for Water Excess Management 367

10.4 Hydrologic Frequency Analysis 373

10.5 U.S. Water Resources Council Guidelines for Flood Flow Frequency Analysis 379

10.6 Analysis of Uncertainties 384

10.7 Risk Analysis: Composite Hydrologic and Hydraulic Risk 387

10.8 Computer Models for Flood flow Frequency Analysis 393

Chapter 11 Water Distribution 397

11.1 Introduction 397

11.2 System Components 409

11.3 System Configuration and Operation 426

11.4 Hydraulics of Simple Networks 429

11.5 Pump Systems Analysis 433

11.6 Network Simulation 448

11.7 Modeling Water Distribution Systems 459

11.8 Hydraulic Transients 461

Chapter 12 Storm water Control: Storm Sewers and Detention 481

12.1 Storm water Management 481

12.2 Storm Sewer Systems 482

12.3 Storm water Drainage Channels 509

12.4 Storm water Detention 517

Chapter 13 Storm water Control: Street and Highway Drainage and Culverts 541

13.1 Drainage of Street and Highway Pavements 541

13.2 Hydraulic Design of Culverts 563

Chapter 14 Design of Spillways and Energy Dissipation for Flood Control Storage and Conveyance Systems 581

14.1 Hydrologic Considerations 581

14.2 Dams 582

14.3 Spillways 593

14.4 Hydraulic-Jump-Type Stilling Basins and Energy Dissipators 616

Chapter 15 Sedimentation and Erosion Hydraulics 637

15.0 Introduction 637

15.1 Properties of Sediment 639

15.2 Bed Forms and Flow Resistance 647

15.3 Sediment Transport 652

15.4 Bed Load Formulas 658

15.5 Suspended Load 663

15.6 Total Sediment Load (Bed Material Load Formulas) 666

15.7 Bridge Scour 674

Supplemental Chapter 15 section 15.8 (Watershed sediment Yield), 15.9 (Reservoir Sedimentation) and 15.10 (Stream Stability at Highway Structures) are available to Instructors for Distribution 15-1

Chapter 16 Water Resources Management for Sustainability 679

16.1 Integrated Water Resources Management for Sustainability 679

16.2 Water Law: Surface and Groundwater Management Aspects 682

16.3 Sustainable Water Supply Methodologies for Arid and Semi-Arid Regions 688

16.4 Water Resources Economics 701

16.5 Water Resource Systems Analysis 708

16.6 Life Cycle Assessment (LCA) 714

16.7 Water-Wise Cities in the Future 717

Chapter 17 Water Withdrawals and Uses (Supplemental Chapter Available to Instructors for Distribution) 17-1

Chapter 18 Water for Hydroelectric Generation (Supplemental Chapter Available to Instructors for Distribution) 18-1

Chapter 19 Flood Control (Supplemental Chapter Available to Instructors for Distribution) 19-1

Appendix A Newton–Raphson Method 723

Index 727